Optimizing inter-joint distances of robotic forceps for vertical needle driving in pediatric surgery: a virtual reality simulator study.

PURPOSE: While related studies have explored robotic forceps adaptations for narrow surgical workspaces, most have focused on horizontal needle driving, with limited research on optimizing robotic forceps configurations for vertical needle driving in pediatric choledochojejunostomy. Moreover, the impact of inter-joint distance adjustments on motion volume and obstructed value for vertical needle driving remains unclear, necessitating further investigation. We aimed to evaluate the effect of inter-joint distances in robotic forceps on a needle driving task that simulated vertical needle driving in a choledochojejunostomy for congenital biliary dilatation in children using a virtual reality simulator. METHOD: We examined the relationship between variations in inter-joint distances, motion volume, and obstructed value. Four pediatric surgeons performed an experimental task, passing a needle through two rings using the right robotic forceps. Based on these results, the inter-joint distances were adjusted through an optimum design approach, which adopted the weighted l p norm method. We then compared the robotic forceps before and after optimization to evaluate changes in the motion volume and obstructed value. RESULTS: We observed a trade-off between motion volume and obstructed value in vertical needle driving. Adjusting inter-joint distances improved motion volume for Participants A, B, and C. However, obstructed value did not improve across all participants. This was attributed to the five-joint robotic forceps used in the study. The impact of inter-joint distances on the obstructed value may be limited when the number of joints remains constant. CONCLUSION: We verified the impact of inter-joint distances on vertical needle driving, considering the narrow surgical workspace and the specific requirements of pediatric surgery. Our findings suggest that adjusting inter-joint distances can improve motion volume in vertical needle driving. However, further investigation is needed to assess its effects across different joint configurations.